The newest version of LoadRunner (version 12.53 patch 4) supports ALPN connections over HTTP/2.

Even though the HTTP/2 standard doesn't require secured SSL connections, all browsers today only implement HTTP/2 over SSL. A special TLS extension called ALPN is necessary in order for the client to announce HTTP/2 over the secure channel to the server.

To record HTTP/2 in VuGen 12.53 patch 4:
In order to record the HTTP/2 traffic, the user should choose the ALPN TLS extension in VuGen' s Recording Options ''Advanced Port Mapping Settings'' dialog. This setting allows TLS ALPN for all TLS sites. If the site isn't using TLS ALPN, the connection will be downgraded to appropriate TLS version (1.2, 1.1, or 1.0).

Below is a link to a great article on this topic, with links to a YouTube video with a demo :
https://www.linkedin.com/pulse/performance-testing-http2-web-applications-scott-moore